Methods, tools, and products for molded ordered porous structures

ABSTRACT

A mold for use in forming form a porous molded product via an injection molding process is provided. The method comprises injecting a material into the mold comprising multiple layers of shaping elements extending through a cavity, each layer of shaping elements including multiple shaping elements; and removing the molded product from the mold, the molded product having a porous structure formed by at least some of the shaping elements of the layers of shaping elements. The porous structure includes a multiplicity of ordered structural members defining the porous structure, the multiplicity of structural members intersecting to form structural member intersections, and a multiplicity of the pores defined by the multiplicity of structural members.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a DIV of and claims priority to U.S. patentapplication Ser. No. 11/848,163, filed on Aug. 30, 2007, now U.S. Pat.No. 7,832,459; the entire contents of which are hereby incorporated byreference herein, for any and all purposes.

BACKGROUND

One-dimensional pore structures are produced through extrusion. Theproduct is usually called the honeycomb structures under the category ofcellular structures.

Two-dimensional pore structures are also produced for heat transferapplications though various methods.

The three-dimensional structures are made through three dominantmethods. These are foaming, foam replication, and solid free forming or3D printing processes.

The foaming or replication process is limited to producing non-uniformpore structures. The geometry of the pores is dictated by the formation,growth, and impingement of gaseous cells. In general, pores arespherical in shape. In addition, the openings are not uniform and thevariation in pore size could be an order of magnitude.

The 3D printing process or solid free forming produces three-dimensionalporous structures by depositing materials using one or several nozzlesat once. This process builds the desired structure layer by layer; it istime consuming, limited to few materials, and costly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 relates to a method for forming and applying a molded orderedporous structure;

FIGS. 2A-D contain multiple views of a mold for forming a molded orderedporous structure where the mold is only partly assembled;

FIG. 3 is a perspective view of the mold of FIG. 2 when fully assembledand closed;

FIGS. 4A-C contain multiple views of a pin carrying body for use withthe mold of FIG. 2;

FIG. 5 is a perspective view of an angled pin receiving body;

FIG. 6 is a perspective view of a pin receiving body which may be usedas a cap in the mold of FIG. 2;

FIGS. 7A-14B illustrate various pin arrangements of the pins of the moldof FIG. 2 and the molded ordered porous structures made from moldscontaining that pin arrangement;

FIGS. 15A&B are an illustration of a molded ordered porous structurehaving hollow centers which replicates the pattern of the pins in themold; and

FIGS. 16A&B are an illustration of a molded ordered porous structurehaving offset struts and an offset pin arrangement for forming thestructure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to FIG. 1, a method of forming an article includes providing amaterial at block 12. The material can be any material usable in a mold.In some embodiments, the material includes one or more of athermoplastic polymer, a thermoset resin, a ceramic, and a metal such asmetal, ceramic, and polymer matrix composites.

In some embodiments, the material can include (at least partially, morethan half, substantially, or essentially) a bio-compatible material suchas a bioresorbable material or a bio-inert material. In some of theseembodiments, the material is a bioresorbable material such as abioresorbable polymer or a bioresorbable ceramic. Examples ofbioresorbable ceramics which may be used include tricalcium phosphates,hydroxyapatite, bioactive glass, etc. Examples of bioresorbable polymersinclude DLPLA-poly(dl-lactide), LPLA-poly(l-lactide), PGA-polyglycolide,PDO-poly(dioxanone), PGA-TMC-poly(glycolide-co-trimethylene carbonate),PGA-LPLA-poly(l-lactide-co-glycolide),PGA-DLPLA-poly(dl-lactide-co-glycolide),LPLA-DLPLA-poly(l-lactide-co-dl-lactide),PDO-PGA-TMC-poly(glycolide-co-trimethylene carbonate-co-dioxanone), PDS,PHV-polyhydroxybutyrate, PHV-polyhydroxyvalerate,PHB-polyhydroxybutyrate, polymers comprising the units, polyesterpolymers (e.g. polyorthoesters), polymers of naturally occurring estersand/or acids, polyanhydrides, polymers containing peptide (amide)linkages, any combination of these materials, copolymers of any of themonomers of the materials described above, substances selected from agroup containing one or more of these materials, etc. In some of theseembodiments, the material is a bio-inert material such as bio-inertpolymer or bio-inert ceramic. Examples of bio-inert ceramics that can beused include compounds including alumina, ziconia, titania, bio-ceramicmaterials, etc. Examples of bio-inert polymers include,polyetheretherketone (PEEK), polycarbonate, polyethylene, PMMA, etc.

In some embodiments, the material can be a heat conducting material suchas a metal-based material, a diamond-containing material, a polymermaterial, or some other heat conducting material. As one example, thematerial may be a stainless steel material. As another example, thematerial may be an alloy such as an alloy made from cobalt and/orchromium.

Once the material is provided at block 12, it is introduced into themold at block 14. Introducing the material to the mold could include anynumber of mold-based forming processes such as injection molding,gravity casting, investment casting, silicone casting, die casting, slipcasting, chemical and vapor deposition methods, dip coating, etc. Thematerial may be heated or placed into solution in order to allow thematerial to be introduced into the mold, and/or any other standardtechnique may be used.

The product is then formed at block 16. With some materials and/orprocesses, the final product is formed at block 16. With other materialsa non-final product (e.g. a green product) is formed at block 16.Forming the product at block 16 preferably involves using a moldaccording to any of the embodiments described herein. The product formedat block 16 may be a molded ordered porous structure (MOPS); a structurecontaining a pre-defined highly porous shape formed by a molding processusing a mold containing the inverse of that highly porous shape.

The formed structure at block 16 may have a porosity (% of volumeoccupied by pores/spaces) of at least about 20%, at least about 25%, atleast about 30%, at least about 35%, at least about 40%, at least about45%, at least about 50%, at least about 55%, at least about 60%, atleast about 65%, and/or at least about 70%.

One, some, substantially all, or essentially all of the pores formed inthe structure may have a cross-sectional area of at least about 2500square micrometers, at least about 0.01 square millimeters, at leastabout 0.1 square millimeters, at least about 0.2 square millimeters, atleast about 1 square millimeter, up to about 1 square centimeter, up toabout 1 square millimeter, up to about 0.5 square millimeters, up toabout 0.3 square millimeters, up to about 0.2 square millimeter, and/orup to about 0.1 square millimeter. In some embodiments, thecross-sectional area may be less than 2500 square micrometers or greaterthan 1 square centimeter.

One, some, substantially all, or essentially all of the pores formed inthe structure may have a cross-sectional diameter (i.e. the averagelength between internal sides of a pore measured from a two-dimensionalcross-section of the pore, the cross-section being perpendicular to thedirection in which the pore extends) of up to about 7 mm, up to about 4mm, up to about 3 mm, up to about 2 mm, up to about 1500 microns, up toabout 800 microns, up to about 400 microns, up to about 200 microns, upto about 150 microns, up to about 125 microns, up to about 100 microns,up to about 80 microns, up to about 50 microns, at least about 20microns, at least about 50 microns, at least about 100 microns, at leastabout 150 microns, at least about 200 microns, at least about 300microns, at least about 400 microns, at least about 600 microns, atleast about 1 mm, and/or at least about 2 mm. Where a pore does not havea uniform diameter, the average cross-sectional diameter can be measuredby picking a point in the center of the pore and measuring (andaveraging) the length of a line extending between internal sides of thepore at every 5 degrees (i.e. rotating the lines by 5 degrees for everymeasurement).

Pores in the molded structure may be designed to be uniform or roughlyuniform. In some embodiments at least 70% or at least 80% or at least90% of the pores that are larger than the average pore size of thestructure have a cross-sectional area that is less than 10 times or lessthan 5 times or less than 2 times the average pore size of thestructure. In some embodiments at least 70% or at least 80% or at least90% of the pores that are smaller than the average pore size of thestructure have a cross-sectional area that is more than one-tenth of ormore than one-fifth of or more than one-half of the average pore size ofthe structure.

Pores in the structure may take many forms. In some embodiments, one ormore pores may include straight portions (e.g. straight portions thatextend under multiple strut members such that a theoretical ray of lightcould be shone from the start of the pore to the end of the pore withoutchanging direction). The straight portions may be internal, or may bearranged such that a pore extends essentially or substantially straightfrom one surface of the structure to another structure of the surface.The structure may include several such straight pores, and may includestraight pores that extend in more than one direction. In someembodiments, a structure may have at least six primary surfaces.Straight pores may extend from a first primary surface to a secondprimary surface, and from a third primary surface to a fourth primarysurface, but not from a fifth primary surface to a sixth primarysurface.

In some embodiments, one or more pores may include portions that extendin a natural direction (e.g. following a straight line, following acurve around a single axis such as a normal curve or an exponentialcurve, or any other direction that does not require a ray of lightfollowing the path of the pore to zig-zag or make other abrupt changesin direction). The straight portions may be internal, or may be arrangedsuch that a pore extends essentially or substantially straight from onesurface of the structure to another structure of the surface. Thestructure may include several such straight pores, and may includestraight pores that extend in more than one direction. In someembodiments, a structure may have at least six primary surfaces.Straight pores may extend from a first primary surface to a secondprimary surface, and from a third primary surface to a fourth primarysurface, but not from a fifth primary surface to a sixth primarysurface.

Any pore may be internal, or may be arranged such that a pore extendsessentially or substantially from one surface of the structure toanother structure of the surface. The structure may include several suchpores, and may include pores that extend in more than one direction.

The molded structure may be entirely a molded ordered porous structure,or may contain a portion (e.g. a surface portion) that contains themolded ordered porous structure. Such a portion shall be referred to asa molded ordered porous structure herein.

As discussed in more detail below, the pores from the molded orderedporous structure may be substantially entirely interconnected throughoutthe molded ordered porous structure.

The structure formed at block 16 may include any of the featuresdiscussed in more detail, below.

Forming the structure may also include removing the structure from themold. Removing the structure from the mold may include removing the pinsfrom the molded structure (e.g. by pulling the pins out of thestructure), removing a cast that takes the shape of the molded article,melting the material that defined the spaces of the structure (e.g.wax-based pins), etc.

In some embodiments, the process for forming may be providedautomatically (e.g. without user intervention). Such a process mayprovide at least 20 structures per hour per mold, such as 20 structuresper hour per mold cavity. In some of these embodiments at least 30, atleast 40, at least 50, and/or at least 60 structures are provided permold and/or per mold cavity per hour. In some embodiments, amulti-cavity mold (e.g. a mold having at least about 5, at least about10, at least about 15, at least about 20, at least about 25, and/or atleast about 30 cavities per mold) is used such that at least about 300,at least about 400, at least about 500, at least about 600, at leastabout 700, at least about 800, at least about 900, at least about 1000,at least about 1250, at least about 1500, and/or at least about 1750structures are produced per mold per hour.

A forming process may include a multi-step forming process. For example,a first material may be used to form a structure having a firstgeometry. A second step may include that structure in a second formingprocess that uses a different material, and/or a different geometry, andresults in a second structure that at least partially includes the firststructure. The second step could comprise filling the pores in the firststructure with a second material having a different composition than thematerial used to make the first structure. Further, the first structurecould be used as a sacrificial structure (e.g. removed to form the finalproduct) used to form the second structure.

Forming the structure may include foaming some, all, or at least a partof the structural members (e.g. struts) (e.g. the structural memberswhich define the pores). Foaming the structure may be configured toreduce the modulus of the structure and/or increase the flexibility ofthe structure. Foaming the structure may include co-injection of a gas(argon, nitrogen, oxygen, etc.), incorporation of foaming agents (e.g.sodium bicarbonate, water, etc.), or some other foaming process.

If a product requires further finishing steps, such steps are performedat block 18. Finishing steps may include degating, debinding theproduct, sintering the product, curing the product, some other heattreatment of the product, etc.

A product may be formed by completely (or substantially completely)filling the spaces in the mold with material, could be formed by coatingthe pins with a material (e.g. such that a structure replicating thepins is formed and having hollow centers—see FIGS. 15A&B), etc. Anycoating technique discussed below could be used.

Once a finished product is formed at block 18, it is prepared forapplication at block 20. Preparing the product for application mayinclude further shaping of the product, applying coatings (e.g. heatconducting coatings, bio-active coatings, biocidal, ion-exchangecoatings, surface area increasing coatings, catalyst coatings,chemically active functional coatings, etc.), etching, leaching, electroplating, etc. Coatings can be applied by dip coating, wash coating,electroplating, slip coating, using a PVD process, using a chemicaldeposition process, using a solvent process, and/or using other coatingprocesses. Any or any combination of the preparing steps (including anyor any combination of the coatings described herein) are contemplated tobe applied, in various embodiments of the applications, to any of theapplications described herein.

Once the product is prepared at block 20, the product can be applied toits application at block 22. Examples of applications to which theproduct can be applied include use in a biological application (e.g. ascaffolding for cell growth such as stem cell growth, a whole or portionof an implant such as a bone replacement implant or a dental implant,etc.), a catalytic converter, a heat sink, an ion-exchange column, acatalyst support, in a packed bed reactor, as a filter of a filtrationapplication, as a radiant heater, as a movable material in a kiln, in anabsorption application such as a desiccant, etc.

Referring to FIGS. 2A to 2D, a mold 102 for use in an injection moldingprocess includes a first pin carrying body 104 configured to carrymultiple pins 116. Pins 116 extend through spaces (e.g. holes, slots,etc.) in spacer body 108. Pins 116 then extend through a space 140defined in part by body 108. Mold 102 is configured such that, in use,pins 116 then extend through spaces (e.g. holes, slots, etc.) in an endspacer body 110 (see, e.g., FIG. 3). Bodies 108 and 110 may beconfigured to maintain pins in an ordered relationship (e.g. by allowingpins 116 to resist deforming forces caused by an injection of materialinto mold 102).

Mold 102 also includes a second pin carrying body 106 configured tocarry multiple pins 114. Pins 114 extend through a second set of spacesin spacer body 108, and then extend through space 140. Mold 102 isconfigured such that pins 114 extend through spaces 120 in an end spacerbody 112. Bodies 108 and 112 may be configured to maintain pins in anordered relationship (e.g. by allowing pins 114 to resist deformingforces caused by an injection of material into mold 102).

Layers of pins 114 can be interlaced with layers of pins 116. Forexample, as shown, a layer of pins 114 may be spaced between each of themultiple layers of pins 116. In many embodiments, pins 114 contact pins116 such that pins 114 and pins 116 form a series of interconnectedspaces in a product molded using mold 102 (see, e.g., product 650 inFIG. 7A). A pin 206 (FIG. 4A) may contact multiple pins 116, includingpins 116 that are horizontally displaced from each other (e.g. pins in acommon layer) and pins that are vertically displaced from each other(e.g. pins from different layers). A point of contact for a pin is aspot where one pin contacts another pin. A single pin may have multiplepoints of contact where that pin contacts multiple pins, separatelycontacts a single pin multiple times, etc. In some embodiments, the pinswithin the mold contain at least 100 points of contact and/or at leastabout 200 points of contact. In some of these embodiments, the pinswithin a mold have at least about 300 points of contact and/or at leastabout 400 points of contact. The spaces may be formed in a smallreticulated structure. In some embodiments, the pins within the moldhave at least any of the above listed number of points of contact withinan area having a volume of up to about 400 cubic millimeters, up toabout 300 cubic millimeters, up to about 200 cubic millimeters, up toabout 100 cubic millimeters, up to about 75 cubic millimeters, up toabout 50 cubic millimeters, up to about 25 cubic millimeters and/or upto about 10 cubic millimeters. As an example, in the embodimentillustrated, many of the pins 114 contact fourteen of pins 116, thuseach of those pins 114 represents 14 points of contact. If there aretwenty-eight pins 114 that each have fourteen points of contact, thenthe total number of points of contact for those twenty-eight pins is392.

This structure may generally also form points of contact for the spacesbetween the pins (e.g. which may be filled with a material to form astructural member of a product formed using the mold). A point ofcontact for a space between the pin is a spot where one space extendingin one direction contacts another space extending in another direction(e.g. in the case of struts and other structural members in a productformed by the mold, it is the location where one structural membercontacts another structural member). A single space may have multiplepoints of contact where that space contacts multiple other spaces,separately contacts a single other space multiple times, etc. In someembodiments, the spaces within the mold (or structural members within aproduct) contain at least 50 points of contact, at least 100 points ofcontact and/or at least about 150 points of contact. In some of theseembodiments, the spaces within a mold (or structural members within aproduct) have at least about 200 points of contact, at least about 250points of contact, at least about 300 points of contact, at least about350 points of contact, and/or at least about 400 points of contact. Thespaces may be formed in a small reticulated structure. In someembodiments, there are at least any of the above listed number of pointsof contact within an area having a volume of up to about 400 cubicmillimeters, up to about 300 cubic millimeters, up to about 200 cubicmillimeters, up to about 100 cubic millimeters, up to about 75 cubicmillimeters, up to about 50 cubic millimeters, up to about 25 cubicmillimeters and/or up to about 10 cubic millimeters.

The pins in the mold may come from any direction, and may cross and/orintersect at any angle. In some embodiments, at least some of the pins114 and 116 in the mold are configured to cross other pins 116 and 114in a space (e.g. space 140) of the mold at an angle (i.e. the smallerangle generated by the crossing) of at least about 15 degrees, at leastabout 30 degrees, up to about 75 degrees, and/or up to about 60 degreeswith respect to at least some of the other pins 116 and 114 of the mold.In some of these embodiments, the pins are configured to cross at anangle of at least about 45 degrees, at least about 60 degrees, and/or atleast about 75 degrees. In some embodiments (e.g. the illustratedexample), at least some of the pins of the mold may be configured tocross the mold at a substantially 90 degree angle to each other. Asillustrated, pins 116 are configured to intersect (cross and contacteach other) at least some of the pins 114 at a roughly 90 degree angle.Some of the pins of the mold may be configured to intersect other pinsof the mold at any of the angles discussed above. Further, some pins maycross each other at one angle, while others of the pins may cross atdifferent angles.

While shown as extending from only two directions in the illustrativeembodiment of FIGS. 2-3, pins may extend into space 140 from any numberof directions. For example, pins extend through a space in the mold from3 directions that are equally spaced (i.e. cross each other at 60 degreeangles) or, as illustrated, extend in. In some embodiments, pins extendinto a space in the mold where material is provided from at least 2directions, at least 3 directions, at least 4 directions, at least fivedirections, up to 12 directions, up to 10 directions, up to 8directions, up to 6 directions, up to 4 directions, and/or up to 3directions. In some embodiments, pins may extend in a singulardirection, or may extend in more than 12 directions.

The directions in which the pins extend may define the direction inwhich the pores extend. Any discussion relating to the characteristicsof the directions in which the pins extend is also applicable todefining potential characteristics of the direction in which the poresof a product made by the mold (or made otherwise) extend.

Bodies 104, 106, and 108 may include spaces 122, 124, and 128 that maybe used to control movement of bodies 104, 106, and 108. For example,one or more tools extending through spaces 122, 124, and 128 may be usedto separate bodies 104, 106, and/or 108. For example, a tool may extendthrough space 124 to pull pins 114 out of a product molded using mold102 while a separate tool extends through space 128 to maintain body 108in a fixed position.

Referring to FIGS. 2A and 3, bodies 104 and 106 may have portions (e.g.ends 202 and 203) that are shaped to conform to each other such thatthey form a substantially seamless exterior surface 152 and/or asubstantially seamless interior surface 154. Bodies 110 and 112 may alsohave portions (e.g. ends 414) that are shaped to conform to each othersuch that they form a substantially seamless exterior surface 156 and/ora substantially seamless interior surface 158. Interior surface 158 maycooperate with interior surface 314 (FIG. 5) of body 108 to form aninterior perimeter of mold 102.

The interior perimeter (e.g. formed in part by surfaces 314 and 158) ofmold 102 defines at least two dimensions of space 140, and may have anyshape. In some embodiments, the interior perimeter may have a shapehaving between three and eight sides. In some of these embodiments, theinterior perimeter may have at least 4 sides (e.g. a rectangular shape)and/or up to six sides.

Referring to FIG. 4A, body 106 is configured to carry a multiplicity ofpins 114. Pins 114 may be arranged in layers 220-228 of pins 214. Inmany embodiments, the pins 214 of a single layer 220 may all be arrangedin roughly the same plane. The multiple layers 220-228 may be arrangedin parallel planes, or may be arranged in some other manner. Pins 214may extend from their base 204 (which, in many embodiments ispermanently connected to body 106) to their tips 208 (which, in manyembodiments, extend through a body 110, 112 when in use).

In some embodiments, body 106 may include at least about 3, at leastabout 5, up to about 15, and/or up to about 20 layers of pins. In someembodiments, body 106 may include less than 3 layers of pins or morethan 20 layers of pins. In some embodiments, body 106 may include divots230 that correspond to its layers of pins.

A single layer 228 of pins may include multiple pins 240-252 (FIG. 4C).According to some embodiments, a single layer 228 of pins may include atleast about 3, at least about 5, up to about 15, and/or up to about 20layers of pins. In some embodiments, a single layer 228 may include lessthan 3 pins or more than 20 pins.

In total, a single body 106 may be configured to carry any number ofpins. In some embodiments, body 106 is configured to carry at leastabout 20 and/or at least about 30 pins. In some of these embodiments,body 106 is configured to carry at least about 35 and/or at least about50 pins.

The pins from the layers of pins may be arranged in an array (e.g. anarray of columns 220-228 and rows 240-252 of pins) or may be arranged insome other manner. Each layer of pins may include the same number ofpins or may include different numbers of pins (e.g. when differentspacing is used, when different thicknesses of pins are used, when themold 102 forms a non-rectangular-box shape, etc.).

As shown in FIG. 4C, each pin 240 may be tapered. The pin 240 may taperfrom its base (e.g. near a pin carrying body 106) to its tip 208 (e.g.away from pin carrying body) such that it narrows from its base to itstip. The pin 240 may only be tapered in a single dimension (e.g. asillustrated in FIGS. 4B and 4C), or may be configured to taper inmultiple directions (e.g. where the pin takes the shape of a pyramid ora cone). If pin 240 only tapers in a single dimension, pin 240preferably tapers along a side that is not configured to contact otherpins 116 (FIG. 2A). Also, if pin 240 tapers, it may taper along itsentire length or may only taper over a portion of its length.

In some embodiments, the base of pin 240 may have a width 280 of atleast about 10 micrometers, at least about 25 micrometers, at leastabout 50 micrometers, at least about 100 micrometers, at least about 200micrometers, at least about 500 micrometers, at least about 1 mm, and/orat least about 3 mm. In some embodiments, the base of pin 240 may have awidth 280 of up to about 30 mm, up to about 15 mm, up to about 7 mm, upto about 5 mm, up to about 1 mm, up to about 500 micrometers, and/or upto about 250 micrometers. In some embodiments, pin 242 may have a widthof less than 10 micrometers or more than 30 mm.

If pin 242 has a width that tapers, pin 242 may taper in someembodiments such that the width 282 of the pin about two thirds awayfrom the base of the pin 240 decreases at least 5%, at least 10%, and/orat least 20% from the width 280 near its base 204 and/or near its widestpoint. In some embodiments, the width 282 of pin 242 may decrease up toabout 50%, up to about 40% and/or up to about 30% from the width 280near its base 204 and/or near its widest point.

A pin may have a height 284, according to some embodiments, of at leastabout 10 micrometers, at least about 25 micrometers, at least about 50micrometers, at least about 100 micrometers, at least about 200micrometers, at least about 500 micrometers, at least about 1 mm, and/orat least about 3 mm. In some embodiments, pin 242 may have a height 284of up to about 30 mm, up to about 15 mm, up to about 7 mm, up to about 5mm, up to about 1 mm, up to about 500 micrometers, and/or up to about250 micrometers. In some embodiments, pin 242 may have a height of lessthan 10 micrometers or more than 30 mm.

If a pin has a height 284 that tapers, the pin may taper in someembodiments such that the height decreases at least 5%, at least 10%,and/or at least 20% from the height near its base and/or near itsthickest point. In some embodiments, the height of the pin may decreaseup to about 50%, up to about 40% and/or up to about 30% from the heightnear its base and/or near its thickest point.

As shown in FIGS. 4B and 4C, pin 242 may include a more severe taper atits tip, such that pin 242 may come to a point. This second taper may belocated at a point that is not exposed to a space 140 of the mold intowhich some or all of the material to be molded is provided.

In some embodiments, pin 242 may have a length of at least about 1 mm,at least about 5 mm, at least about 10 mm, at least about 20 mm, atleast about 40 mm, and/or at least about 80 mm. In some embodiments, pin242 may have a length of up to about 400 mm, up to about 200 mm, up toabout 100 mm, up to about 75 mm, up to about 50 mm, up to about 40 mm,up to about 30 mm, up to about 20 mm, and/or up to about 10 mm. In someembodiments, pin 242 may have a length less than 1 mm or more than 400mm.

Each of pins 114 may have the same potential properties as discussedabove for pins 240, 242 or may have different properties. Further, eachof pins 114 may be the same, or some or all may be different.

Body 104 and pins 116 carried by body 104 can have the same propertiesas body 106 and pins 114 carried by body 106.

Mold 102 (FIG. 2) may include at least about 40 and/or at least about 60pins. In some of these embodiments, mold 102 may include at least about70 and/or at least about 90 pins. In some embodiments, mold 102 mayinclude less than about 200, less than about 150, and/or less than about100 pins. In some embodiments, mold 102 may include less than 40 or morethan 200 pins.

The pins 116 and pin carrying body 104 can be an integral piece, can bepermanently connected to each other, can be removably connected to eachother, some other configuration, or a combination of theseconfigurations.

A multiplicity of pins 114, 116, etc. (e.g. 10 or more, 20 or more, 30or more, 40 or more, all, almost all, etc.) may have substantially thesame (e.g. within 5%, within 10%, and/or within 20%) cross-sectionalarea and/or shape as each other.

A product made using pins 114, 116 may include tool marks where pins114, 116 have been removed, where the product contacted pin carryingbodies 104, 106, and/or other tool marks.

Referring to FIG. 5, mold 102 (FIG. 2A) may include a body 108configured to include spaces 310, 312 through which pins can extend.Spaces 310, 312 may be configured to have roughly the same dimensionsand/or shape as the pins and/or portions of pins that extend throughthem, and the spaces may include any of the dimensions discussed abovefor pins 240, 242. As shown in FIG. 5, spaces 318 near the surface ofbody 108 may be formed as grooves. Also, the spaces 310, 312 arepreferably arranged in the same or similar pattern to the pattern inwhich the pins are arranged.

Spaces 310 or 312 may all be the same, or may be different. For example,all the spaces may be roughly the same shape and dimensions organized inan array. As another example, if a pin carrying body includes some pinsthat extend perpendicular to body 108 and others that do not extendperpendicular to body 108, then body 108 may include spaces that arestraight uniform spaces and others that are wider at the surface facingthe pin carrying body and narrower at the surface facing space 140 (FIG.1).

A single body 108 may include spaces 310, 312 configured to receive pinscarried by multiple pin carrying elements 104, 106. Such a body 108 mayinclude one or more bends 316 that change the direction in which thebody 108 extends. The bend may be abrupt (as shown) or may be smooth(e.g. curved).

Body 108 may include at least 20, at least 30, at least 40, at least 60,at least 80, and/or at least 100 spaces configured to receive pins.

In some embodiments, one, some, or all of spaces 310, 312 may have across sectional area of at least about 2500 square micrometers, at leastabout 0.01 square millimeters, at least about 0.1 square millimeters, atleast about 0.2 square millimeters, at least about 1 square millimeter,up to about 1 square centimeter, up to about 1 square millimeter, up toabout 0.5 square millimeters, up to about 0.3 square millimeters, up toabout 0.2 square millimeter, and/or up to about 0.1 square millimeter.In some embodiments, the cross-sectional area may be less than 2500square micrometers or greater than 1 square centimeter.

Referring to FIG. 6, a pin receiving body 112 includes a multiplicity ofspaces 120. Spaces 120 may be configured to have roughly the samedimensions and/or shape as the pins and/or portions of pins that extendthrough them, and the spaces may include any of the dimensions discussedabove for pins 240, 242. As shown in FIG. 6, spaces 416 near the surfaceof body 112 may be formed as grooves. Also, the spaces 120 arepreferably arranged in the same or similar pattern to the pattern inwhich the pins are arranged.

Spaces 120 may all be the same, or may be different. For example, allthe spaces may be roughly the same shape and dimensions organized in anarray. Body 112 may include at least 20, at least 30, at least 40, atleast 60, at least 80, and/or at least 100 spaces configured to receivepins.

In some embodiments, one, some, or all of spaces 120 may have a crosssectional area of at least about 2500 square micrometers, at least about0.01 square millimeters, at least about 0.1 square millimeters, at leastabout 0.2 square millimeters, at least about 1 square millimeter, up toabout 1 square centimeter, up to about 1 square millimeter, up to about0.5 square millimeters, up to about 0.3 square millimeters, up to about0.2 square millimeter, and/or up to about 0.1 square millimeter. In someembodiments, the cross-sectional area may be less than 2500 squaremicrometers or greater than 1 square centimeter. In some embodiments,the cross-sectional area of a space 120 through which a pin isconfigured to extend may be about the same as the cross-sectional areaof a space 310,312 in body 108 through which that pin is configured toextend. In some embodiments, the cross-sectional area of a space 120through which a pin is configured to extend may be less than thecross-sectional area of a space 310, 312 in body 108 through which thatpin is configured to extend.

Body 112 may include a face 410 configured to extend at an angle withrespect to the face 418 through which the pins extend. In someembodiments, face 410 may extend at an angle of at least about 15degrees, at least about 30 degrees, up to about 60 degrees, and/or up toabout 75 degrees. Face 410 may contain a partial cut-out 412 (e.g. asemi-circular space), which may be used by a tool to remove the moldedproduct from the mold.

While referred to as pins 114, 116, the same disclosure is relevant toany space forming element such as pins, cores, or other shaping elementsfor creating spaces in a molded product. The space forming elements mayhave any shape whether straight, curved, multi-sided, single sided,regularly shaped, irregularly shaped, uniformly thick, non-uniformlythick (e.g. ordered non-uniform such as tapered, disordered non-uniformsuch as random thickness), etc. Each of the space forming elements maybe solid, may be hollow, may have a single composition throughout, mayhave a varying composition, may include outer coatings on substantiallyall or portions of its surface, and/or may have any other property. Eachof the space forming elements carried by a body and/or in a mold may beroughly the same (i.e. the same or close to the same) shape and/or size,some may be roughly the same shape and/or size, none may be the sameshape and/or size, etc.

While spacer body 108 is shown as a single piece, in some embodiments,spacer body 108 may be formed from more than one piece. Also, whileconvenient to have multiple end spacer bodies 110, 112, a system couldinclude a single end spacer body. Further, in some embodiments, mold 102may not include a spacer body 108 or an end spacer body 110 or 112.References to spacer bodies 108, 110, and 112 are equally applicable toany type of body, including non-spacer bodies.

While shown as extending straight across, any of the pins discussedabove may be curved (fully or partially) or take any other shape.

A structure made according to any of the embodiments above may haveintersecting struts that are essentially continuous and/or essentiallyfluid (e.g. have no major gaps between layers of struts at theintersections of those layers other than that caused by the materialgenerally or are caused by the particular tool design). In someembodiments, a structure has a multiplicity of (e.g. at least about 20,30, 40, 50, 60, 80, 100, 150, 200, 250, etc.), substantially all,essentially all, or all strut intersections (e.g. joints) that areessentially continuous and/or essentially fluid.

A structure made according to any of the embodiments discussed above maybe configured to be flexible (e.g. capable of make a 45 degree bend),essentially flexible (e.g. capable of making at least a 15 degree bend),essentially rigid (not flexible or essentially flexible), and/or rigid(e.g. not capable of making a 5 degree bend). A structure made accordingto any of the embodiments above may have a first portion that is rigid(and/or essentially rigid) while have a second portion that is flexible(and/or essentially flexible). Also, a structure made according to anyof the embodiments above may have at least a portion that is essentiallyflexible but not flexible and/or may have at least a portion that isessentially rigid but not rigid.

A structure made according to any of the embodiments above may becapable of making a bend of at least about 10, at least about 20, atleast about 30, at least about 45, at least about 60, at least about 90,at least about 100 degree, at least about 120 degrees, at least about150 degrees, and/or at least about 170 degrees. A structure madeaccording to any of the embodiments above may be capable of making abend of no more than 170 degrees, no more than about 150 degrees, nomore than about 120 degrees, no more than about 100 degrees, no morethan about 90 degrees, no more than about 60 degrees, no more than about45 degrees, no more than about 30 degrees, no more than about 20degrees, and/or no more than about 10 degrees. The bend may form a sharpangle, may occur smoothly over a length of the structure, etc.

A structure according to any of the embodiments discussed above may alsohave resilient flexibility (i.e. the ability to be compressed like asponge). A structure according to any of the embodiments described abovemay have sufficient resilient flexibility that it can be resilientlycompressed (i.e. compress under pressure and then substantiallyuncompress when the pressure is removed) to at 90% of its volume, can becompressed to at least 85% of its volume, can be compressed to at least80% of its volume, can be compressed to at least 75% of its volume, canbe compressed to at least 70% of its volume, can be compressed to atleast 65% of its volume, can be compressed to at least 60% of itsvolume, can be compressed to at least 50% of its volume, can becompressed to at least 40% of its volume, and/or can be compressed to atleast 30% of its volume.

A structure according to any of the embodiments described above mayinclude a foaming agent in one or more structural members of thestructure.

A porous structure according to any of the embodiment discussed abovemay comprise a multiplicity of ordered structural members defining theporous structure having pores that extend in three dimensions, themultiplicity of structural members intersecting to form structuralmember intersections, substantially all of the structural memberintersections being essentially fluid, and a multiplicity of the poresdefines by the multiplicity of structural members substantiallyextending in a natural direction. The multiplicity of structural membersmay comprise at least about 100 points of contact within an area of upto about 1000 cubic millimeters.

A structure made according to any of the embodiments disclosed above mayinclude structural members which are porous. The pores of the structuralmembers may be ordered or may be unordered (e.g. may have randomlyvarying sizes and/or may be arranged in an irregular pattern).

The pores defined by structural members may be arranged in a regularand/or repeating pattern. As discussed above, the pores (e.g. all,substantially all, some, etc.) may be about a same size and/or shape aseach other.

Any of the tools shown in FIGS. 2-6 may be formed by any number ofdifferent processes. For example, the tools (e.g. pins, pin carryingbodies, pin receiving bodies, etc.) can be formed by a molding process,electro-discharge machining (EDM) (e.g. micro EDM), a laser formingprocess, a chemical process (e.g. a chemical etching process), aphoto-forming process, etc.

Examples of molds and products made by the molds are shown with respectto FIGS. 7A to 16B.

Referring to FIGS. 7A and 7B, a molded product 650 made using a mold asdescribed above, the mold having pins 612-618 overlapping in space 610as shown in FIG. 7B when the mold is joined and closed. Pins 612-618 arerectangular pins having four surfaces. The pins have a greater widththan their height.

Molded ordered porous structure 650 includes multiple spaces 652,654that correspond in shape and dimension to pins 612-618. Spaces 652 and654 are interconnected through the various points of contact of thespaces in molded ordered porous structure 650. Molded ordered porousstructure 650 also includes struts 660 that are configured to providesupport to and define structure 650. Struts 660 correspond in shape anddimension to the spaces between pins 612-618.

Referring to FIGS. 8A and 8B, a molded product 750 is made using a moldas described above, the mold having pins 712-718 overlapping in space710 as shown in FIG. 8B when the mold is joined and closed. Pins 712-718are trapezoidal pins having four surfaces.

Molded ordered porous structure 750 includes multiple spaces 752,754that correspond in shape and dimension to pins 712-718. Spaces 752 and754 are interconnected through the various points of contact of thespaces in molded ordered porous structure 750. Molded ordered porousstructure 750 also includes struts 760 that are configured to providesupport to and define structure 750. Struts 760 correspond in shape anddimension to the spaces between pins 712-718.

Referring to FIGS. 9A and 9B, a molded product 850 is made using a moldas described above, the mold having pins 812-818 overlapping in space810 as shown in FIG. 9B when the mold is joined and closed. Pins 812-818are square pins having four surfaces.

Molded ordered porous structure 850 includes multiple spaces 852,854that correspond in shape and dimension to pins 812-818. Spaces 852 and854 are interconnected through the various points of contact of thespaces in molded ordered porous structure 850. Molded ordered porousstructure 850 also includes struts 860 that are configured to providesupport to and define structure 850. Struts 860 correspond in shape anddimension to the spaces between pins 812-818.

Referring to FIGS. 10A and 10B, a molded product 950 is made using amold as described above, the mold having pins 912-918 overlapping inspace 910 as shown in FIG. 10B when the mold is joined and closed. Pins912-918 are partially ovals having a single curved surface. The pins912,914 contact pins 918 on opposite sides of the surface of pins 918 onan elongated or flat portion of the surface such as that represented bythe rectangular area 920 shown in FIG. 10B.

Molded ordered porous structure 950 includes multiple spaces 952,954that correspond in shape and dimension to pins 912-918. Spaces 952 and954 are interconnected through the various points of contact of thespaces in molded ordered porous structure 950. Molded ordered porousstructure 950 also includes struts 960 that are configured to providesupport to and define structure 950. Struts 960 correspond in shape anddimension to the spaces between pins 912-918.

Referring to FIGS. 11A and 11B, a molded product 1050 is made using amold as described above, the mold having pins 1012-1018 overlapping inspace 1010 as shown in FIG. 11B when the mold is joined and closed. Pins1012-1018 are plus-shaped and have twelve surfaces.

Molded ordered porous structure 1050 includes multiple spaces 1052,1054that correspond in shape and dimension to pins 1012-1018. Spaces 1052and 1054 are interconnected through the various points of contact of thespaces in molded ordered porous structure 1050. Molded ordered porousstructure 1050 also includes struts 1060 that are configured to providesupport to and define structure 1050. Struts 1060 correspond in shapeand dimension to the spaces between pins 1012-1018.

Referring to FIGS. 12A and 12B, a molded product 1150 is made using amold as described above, the mold having pins 1112-1118 overlapping inspace 1110 as shown in FIG. 12B when the mold is joined and closed. Pins1112-1118 are hexagons having six surfaces.

Molded ordered porous structure 1150 includes multiple spaces 1152,1154that correspond in shape and dimension to pins 1112-1118. Spaces 1152and 1154 are interconnected through the various points of contact of thespaces in molded ordered porous structure 1150. Molded ordered porousstructure 1150 also includes struts 1160 that are configured to providesupport to and define structure 1150. Struts 1160 correspond in shapeand dimension to the spaces between pins 1112-1118.

Referring to FIGS. 13A and 13B, a molded product 1250 is made using amold as described above, the mold having pins 1212-1218 overlapping inspace 1210 as shown in FIG. 13B when the mold is joined and closed. Pins1212-1218 are parallelograms having four surfaces.

Molded ordered porous structure 1250 includes multiple spaces 1252,1254that correspond in shape and dimension to pins 1212-1218. Spaces 1252and 1254 are interconnected through the various points of contact of thespaces in molded ordered porous structure 1250. Molded ordered porousstructure 1250 also includes struts 1260 that are configured to providesupport to and define structure 1250. Struts 1260 correspond in shapeand dimension to the spaces between pins 1212-1218.

Referring to FIGS. 14A and 14B, a molded product 1350 is made using amold as described above, the mold having pins 1312-1318 overlapping inspace 1310 as shown in FIG. 14B when the mold is joined and closed. Pins1312-1318 are cylindrical rods having a single surface.

Molded ordered porous structure 1350 includes multiple spaces 1352,1354that correspond in shape and dimension to pins 1312-1318. Spaces 1352and 1354 are interconnected through the various points of contact of thespaces in molded ordered porous structure 1350. Molded ordered porousstructure 1350 also includes struts 1360 that are configured to providesupport to and define structure 1350. Struts 1360 correspond in shapeand dimension to the spaces between pins 1312-1318.

Referring to FIGS. 15A&B, a molded ordered porous structure 1410includes a plurality of struts 1412-1420. The plurality of strutscontain holes/spaces 1422-1430 within the struts which are formed in ageneral shape of the pins (not illustrated) used to form the structure1410. In the embodiment illustrated, the holes/spaces 1422-1430 areinterconnected in three dimensions and extend to the surfaces of thestructure in two dimensions. However, the holes 1422-1430 could beformed to extend to the surface in three dimensions by not coating thetop of the pins at the top of the mold, by using a third set of pinsextending in a third dimension, etc.

The struts 1412-1420 also include spaces 1432-1440 between the strutswhich correspond to spaces between the pins used to form structure 1410.In the embodiment illustrated, spaces 1432-1440 are interconnected inthree dimensions and extend to the surface of structure 1410 in threedimensions.

In the embodiment illustrated, spaces 1422-1430 do not interconnect withspaces 1432-1440. Thus, spaces 1422-1440 define two independent poresystems.

Referring to FIGS. 16A and 16B, a molded product 1550 is made using amold as described above, the mold having pins 1512-1518 overlapping inspace 1510 as shown in FIG. 16B when the mold is joined and closed.

Molded ordered porous structure 1550 includes multiple spaces 1552,1554that correspond in shape and dimension to pins 1512-1518. Spaces 1552and 1554 are interconnected through the various points of contact of thespaces in molded ordered porous structure 1550. The spaces extendsubstantially straight in a first direction 1580 and a second direction1582, but follow a tortuous (non-straight, non-natural) path in a thirddirection 1584 because the struts 1560 that define the structure (andthe pins 1512-1518 of the mold used to define the spaces) are offset inthat third direction.

Molded ordered porous structure 1550 also includes struts 1560 that areconfigured to provide support to and define structure 1550. Struts 1560correspond in shape and dimension to the spaces between pins 1512-1518.Struts 1560 are also offset such that two adjacent layers that extend inthe same direction (i.e. the next layer that extends in roughly the samedirection as the reference layer) are offset from each other such thatthe struts do not fully (or essentially) overlap.

While spaces are shown in FIG. 16A as being off-set in only onedirection, the spaces may be off-set in multiple directions. Also, asimilar effect could be achieved, at least in part, by using multiplelayers of pins that extend in more than two directions. Additionally,while the struts from adjacent layers that extend in the same directionare shown as having no overlap, in some embodiments the struts in theselayers will overlap at least one or at least two struts from theadjacent layer.

Any of the dimensions discussed herein for items having a parameter thatis variable across the item can be for the minimum dimension of the itemfor the parameter, the maximum dimension of the item for the parameter,and/or the average dimension of the item for the parameter. All suchpossibilities are expressly considered, including applying all suchcombinations of the dimensions (e.g. a pin may have a maximum heightless than 1 mm and an average height less than 500 microns).

It should be understood that the dimensions and other characteristics ofthe mold above equally define the product that can be made by the mold.Any characteristic of the mold discussed above should also be taken as adescription of a characteristic of a product made by the mold. Forexample, any characteristic of a pin of the mold would be acharacteristic of a space of the molded product. As a specific example,a pin of the mold that tapers is equally a description of a space in thefinished product that tapers. Any dimensions listed above for the pinsare also to be taken as potential dimensions for the spaces of themolds. Also, any description of potential arrangements and/or contactsof pins above would also be a description of potential arrangementsand/or contacts of the spaces of a product made from the mold.Additionally, any description of potential arrangements and/or contactsof spaces between pins above would also be a description of potentialarrangements and/or contacts of the struts or other structural member ofa product made from the mold. All such characteristics of the mold thatare also applicable to a product made from the mold are contemplatedherein as potential characteristics of the products even where notspecifically recited, and should be considered part of the novel subjectmatter contemplated by the inventors. Additionally, the reverse is alsotrue; any characteristic of a product made from a mold that is alsoapplicable as a characteristic of a mold used to make the product, iscontemplated herein even where not specifically recited, and should beconsidered part of the novel subject matter contemplated by theinventors.

Also, any dimension disclosed herein with more than one of thatstructure (e.g. pins or other shaping elements, pores, struts, spaces,etc.) disclosed herein may be applied (if specifically recited in aclaim below) to an individual structure; a plurality of the recitedstructures; multiple of the recited structures; substantially all of therecited structures; essentially all of the recited structures; anaverage of a plurality, multiplicity, substantially all, essentiallyall, or all of the recited structures; or a typical average (i.e. anaverage that excludes the 30% most extreme values of the recitedstructures) of a plurality, multiplicity, substantially all, essentiallyall, or all of the recited structures. All such combinations arecontemplated below. Further, unless recited otherwise in the claim, aclaim to a dimension is a claim to at least one individual structurehaving a particular dimension. Unless stated otherwise, the inclusion ofstructures not meeting the dimension would not exclude them fromcoverage where the required number of structures meeting the dimensionrequirements are present.

Also, any dimension disclosed herein may be applied (if specificallyrecited in a claim below) to an individual pin/element; a plurality ofpins/elements; multiple pins/elements; substantially all pins/elements;essentially all pins/elements; an average of a plurality, multiplicity,substantially all, essentially all, or all pins/elements; or a typicalaverage of a plurality, multiplicity, substantially all, essentiallyall, or all pins/elements. All such combinations are contemplated below.

Also, any disclosure of a list of materials that may be used includesstructures consisting or consisting essentially of one or more of thelisted materials, and/or comprising any combination of two or more ofthe listed materials. All such combinations are contemplated.

Additionally, any reference to something occurring within an area havinga volume should be judged based on an area having a regular shape (e.g.sphere, cube, etc.) and/or a shape matching that of the space of themold if such a shape is not, nor is approximately, a regular shape.

Reference to bioresorbable materials can be a reference to materialsthat degrade through bioerosion, bioresorption, and/or bioabsorption.

EXAMPLES

The following examples are provided by way of example only are notintended to be limiting. Additional features of the invention are seenin the following examples, including the various features shown in thecharts; those discussed in the text and those not specifically discussedin the text.

Example 1

A bioresorbable ceramic material is made using the mold-based formingprocess discussed above. A tri-calcium phosphate (TCP) injection moldingfeedstock was prepared according to the formulation shown in thefollowing table.

Tri calcium Phosphate 448 g ± 1 g  Paraffin wax 36.00 g + 0.05 gPolyethylene 15.25 g + 0.05 g Polypropylene 46.00 g + 0.05 g Stearicacid  6.25 g + 0.05 g

The structure was molded using a Arburg Allrounder 420S injectionmolding machine and a Regoplas 150S mold temperature control unit usingthe following parameters:

Melt temperature (° C.) 188 Tool temperature (° C.) 43 Injection speed25 (cm³/sec) Packing pressure (bar) 1200 Hold time (s) 2 Cooling time(s) 18

The TCP feedstock was injection molded into ordered core structure shownin FIGS. 2-5. The green ceramic structure was then debound in heptane at60° C. to remove wax, to 600° C. to remove the polyethylene,polyproplene, and stearic acid, and to 1150° C. for 5 hours to sinter.

The final sintered TCP structure had openings of about 300 μm by 400 μm.

The compression strength of this TCP structure is about 100 MPa. Thiscompression strength is several orders of magnitude higher than asimilar structure made by slip coating a foam with TCP.

Example 2

A structure is made as disclosed in Example 1 and has opening of about125 μm by about 125 μm.

Example 3

A structure is made as disclosed in Example 1. The structure is coatedwith a polymer such that it contains medicine and/or drugs within thespaces defined by the struts of the structure.

Example 4

A structure is made as disclosed in Example 1. The structure is coatedwith a liquid such that it contains medicine and/or drugs within thespaces defined by the struts of the structure.

Example 5

A structure is made as disclosed in Example 1. The structure isintroduced to a source of cells such that cells can grow within thestructure.

Example 6

A bio-inert ceramic material is made using the mold-based formingprocess discussed above, using an injection molding feedstockcommercially available as Catamold AO-F. This feedstock is 99.8%α-alumina in a polyethylene/polyacetal matrix. An ordered porousstructure of alumina was produced by injection molding the Catamold AO-Fwith the mold described above on an injection molding machine. Thestructure was molded using a Airburg Allrounder 420S injection moldingmachine and a Regoplas 150S mold temperature control unit using thefollowing parameters:

Melt temperature (° C.) 193 Tool temperature (° C.) 132 Injection speed25 (cm³/sec) Packing pressure (bar) 1200 Hold time (s) 2 Cooling time(s) 18

The structures were formed in the shape of cubes. The cubes weremeasured for outside dimensions and the mass was obtained to calculatethe bulk density. Some error was introduced because some struts brokeout when the gate was removed.

Compression strength was measured for these structures using theprocedure detailed above. If the cubes were “edge” loaded rather thanface loaded this caused a higher amount of localized stress leading to alower overall compressive stress value.

Bulk Por- Sample Length Width Height Weight Density osity Material #(mm) (mm) (mm) (g) (g/cc) % % 1 5.49 5.56 4.34 0.255 1.92 49 51 2 5.615.49 4.34 0.259 1.94 50 50 3 5.54 5.59 4.32 0.254 1.90 49 51 4 5.46 5.594.32 0.256 1.94 50 50 5 5.4 5.55 4.41 0.252 1.91 49 51 6 5.44 5.55 4.30.256 1.97 51 49 7 5.58 5.42 4.37 0.258 1.95 50 50 8 5.31 5.55 4.490.255 1.93 49 51 9 5.49 5.56 4.27 0.253 1.94 50 50 10 5.44 5.56 4.30.251 1.93 49 51 11 5.44 5.56 4.28 0.246 1.90 49 51 12 5.51 5.56 4.30.258 1.96 50 50 13 5.4 5.55 4.35 0.256 1.96 50 50 14 5.41 5.57 4.490.259 1.91 49 51 15 5.51 5.56 4.29 0.252 1.92 49 51 16 5.39 5.56 4.590.26 1.89 48 52 17 5.36 5.55 4.35 0.253 1.96 50 50 18 5.41 5.56 4.450.259 1.93 50 50 19 5.42 5.55 4.45 0.259 1.93 50 50 20 5.42 5.57 4.320.25 1.92 49 51

Breaking Comp. Sample force Deflection Stress Modulus # Newtons Mm MPaStrain MPa 1 5179 0.278 169.67 0.06 2648.77 2 5082 0.27 165.01 0.062652.32 3 3969 0.265 128.16 0.06 2089.28 4 5316 0.287 174.17 0.072621.70 5 2099 0.4 70.04 0.09 772.15 6 5987 0.229 198.30 0.05 3723.49 74262 0.295 140.92 0.07 2087.56 8 3012 0.334 102.20 0.07 1373.94 9 50500.25 165.44 0.06 2825.74 10 2228 0.43 73.66 0.10 736.62 11 1725 0.35157.03 0.08 695.43 12 5349 0.278 174.60 0.06 2700.66 13 4901 0.305 163.530.07 2332.32 14 7280 0.232 241.59 0.05 4675.60 15 3743 0.298 122.18 0.071758.87 16 4261 0.262 142.18 0.06 2490.92 17 2988 0.396 100.44 0.091103.36 18 3253 0.314 108.15 0.07 1532.65 19 4509 0.365 149.90 0.081827.49 20 3487 0.32 115.50 0.07 1559.31

The average values for these parameters is shown in the following table.

Parameter Average Std. Deviation Bulk Density (g/cc) 1.93 0.02 Porosity(%) 49.51 0.58 Material (%) 50.49 0.58 Breaking Force 4184.00 1400.56(Newtons) Deflection (mm) 0.31 0.06 Comp. Stress (MPa) 138.13 45.92Strain 0.07 0.01 Moldulus (MPa) 2110.41 1004.21

The parts made through this example would have a compression strength atleast one order of magnitude greater than a similar product made by slipcoating a reticulated foam.

Example 7

A mold-based forming process was used to form a stainless steelstructure. Stainless steel alloy Catamold 316 feedstock supplied by BASFwas molded into the ordered structure using a mold as shown in FIGS.2-6. The structure was molded using a Airburg Allrounder 420S injectionmolding machine and a Regoplas 150S mold temperature control unit usingthe following parameters:

Melt temperature (° C.) 193 Tool temperature (° C.) 132 Injection speed25 (cm³/sec) Packing pressure (bar) 1200 Hold time (s) 2 Cooling time(s) 18

The molded structure was then debound and sintered to form a dense andrigid structure. The molded samples first debind at 110° C. in HNO₃ toensure the extraction of the acetal base polymer of alloy 316. Thedebound samples were then sintered by heating to 600° C. with a heatingrate of 5° C./min, holding for an hour at this temperature followed byheating to 1380° C. with a heating rate of 5° C./min, and holding atthis temperature for three hours in hydrogen.

The openings of the sintered structure were about 300 μm by 400 μm. Thestruts were fully dense. If less dense struts are required, lowersintering temperature could be used.

Example 8

A structure is made as disclosed in Example 7, except that a Co—Cr alloyis used to form the structure instead of the stainless steel alloy.

Example 9

The structure of example 8 is formed as in example 8. The structure isthen shaped for use as an implant. The spaces in the structure are usedas channels for bone growth.

Example 10

A mold-based forming process was used to form a polymer structure. CAPA6500 polycaprolactone supplied by Solvay was molded into ordered porousstructures using the mold shown above in FIG. 2. Polycaprolactone is ahigh molecular weight polyester which has biodergradable properties. Thestructure was molded on a Nissei injection molding machine under thefollowing conditions:

Melt Temperature (° C.) 60 Tool Temperature (° C.) 23 Injection Speed5.16 (cm³/sec) Packing Pressure (bar) 21 Hold Time (s) 12 Cooling Time(s) 20

Example 11

A structure is made as described in Example 10. This structure is usedas an implant for use with a tissue and/or bone replacement system. Thepores and channels produced though this process are inducive for boneand tissue ingrowth. After molding and sterilization, one or morebiologically active coatings can be applied onto the surfaces of thestruts of the structure to promote growth and/or degradation.

Example 12

A mold-based forming process was used to form a polymer structure. CAPA6500 polycaprolactone (PCL) supplied by Solvay was molded into orderedporous structures using the mold shown above in FIG. 2. The PCL materialis gravity cast into the mold. The PCL is heated past its melting pointof about 58-60° C. to melt the PCL, and is poured into the mold as shownin FIG. 2. The PCL is allowed to solidify, forming the ordered porousstructure as shown in FIG. 15.

Example 13

A mold-based forming process was used to form a polymer molded orderedporous structure using polyetheretherketone (PEEK). 406G PEEK suppliedby Victrex was molded into ordered porous structures using the moldshown above in FIG. 2. The structure was molded on a Nissei injectionmolding machine under the following conditions:

Melt Temperature (° C.) 390 Tool Temperature (° C.) 143 Injection Speed8.6 (cm³/sec) Packing Pressure (bar) 193 Hold Time (s) 7 Cooling Time(s) 33

Example 14

A molded ordered porous structure is formed as disclosed in Example 13.The surface of the structure is roughened.

Example 15

A molded ordered porous structure is formed as disclosed in Example 13.The structure is then formed into an implant. The structure includesopenings which promote living cell growth. In addition, since theopenings are also connected internally, the cells would connect to eachother internally after penetrating through the surface.

Example 16

An implant is formed through standard techniques and includes surfacelayers having a molded ordered porous structure as disclosed in Example13.

Example 17

An implant is made in a mold. The mold includes a solid portion at acenter of the mold, and a plurality of pins configured to form a moldedordered porous structure at a surface of the implant.

Example 18

Molded ordered porous structures are formed as in Examples 13, 16, and17. The internal surfaces within the spaces are coated with one or morematerials which are known to promote cell growth and/or cell adhesion.

Example 19

Molded ordered porous structures are formed as in Examples 13, 16, and17. One or more bioactive (conductive, degradable, inductive, etc.)substances are blended into the PEEK material during molding.

Example 20

Molded ordered porous structures are formed as in Examples 13, 16, and17. The structure is used in a vertebral body spacer.

Example 21

A mold-based forming process was used to form a polymer molded orderedporous structure using polycarbonate. Lexan brand polycarbonate suppliedby General Electric Plastics was molded into ordered porous structuresusing the mold shown above in FIG. 2. The structure was molded on aNessei injection molding machine under the following conditions:

Melt Temperature (° C.) 282 Tool Temperature (° C.) 66 Injection Speed60 (cm³/sec) Packing Pressure (bar) 21 Hold Time (s) 6 Cooling Time (s)22

Example 22

A mold-based forming process was used to form a polymer molded orderedporous structure using siloxane. Polymethylenesiloxane type siloxanesupplied by Dow Chemical was molded into ordered porous structures usingthe mold shown above in FIG. 2. The structure was gravity cast under thefollowing conditions:

Resin/catalyst ratio (10:1) Mix Time (minutes) 15 Degas in vacuum  5(minutes) Cure Time (hours)  4 Cure Temperature (° C.) 22

Example 23

A mold-based forming process was used to form a polymer molded orderedporous structure using polyethylene. LM6007-00 polyethylene supplied byEquistar was molded into ordered porous structures using the mold shownabove in FIG. 2. The structure was molded on a Nissei injection moldingmachine under the following conditions:

Equistar LM6007-00 (polyethylene)

Melt Temperature (° C.) 184 Tool Temperature (° C.) 26 Injection Speed(cm³/sec) 9 Packing Pressure (bar) 28 Hold Time (s) 8 Cooling Time (s)22

Example 24

A mold-based forming process is used to form a polymer molded orderedporous structure using polydimethyl silicone. Polydimethylsiliconesupplied by Dow Chemicals is molded into ordered porous structures usingthe mold shown above in FIG. 2. The structure can be molded on an Arburginjection molding machine.

Example 25

A mold-based forming process was used to form a titanium structure.Catamold Ti brand titanium feedstock supplied by BASF was molded intothe ordered structure using a mold as shown in FIGS. 2-6. The structurewas formed on an Arburg Allrounder 420S molding machine using thefollowing process conditions:

Materials Pure Titanium feedstock Catamold Ti Melt temperature (° C.)193 Tool temperature (° C.) 132 Injection speed  25 (cm³/sec) Packingpressure (bar) 1200  Hold time (s)  2 Cooling time (s)  18

Example 26

For application to an implant, a single structure may be formed in theshape to be implanted. Additional materials may be applied to thestructure (e.g. in the spaces of the structure) to aid in theeffectiveness of the implant. These additional materials may includedrugs, medicine, materials that promote cell growth and/or adhesion,etc.

Example 27

For another application to an implant, multiple structures are formed.The structures are held together within an enclosed portion of a shapedarticle that is formed in the shape to be implanted. Additionallybio-active materials may be added as discussed in the previous example.

Example 28

For an application to a catalytic converter, a molded ordered porousstructure is formed using a ceramic, a stainless steel, or some othermaterial. A washcoat (e.g. made from silica and/or alumina) is thenapplied to the structure including within the pores. One or morecatalysts (e.g. palladium, rhodium, platinum, cerium, iron, nickel,manganese, etc.) are then placed in the structure.

The structure is then placed in an exhaust system between an engine'sexhaust outlet (e.g. the exhaust valve) and the outside environment.Sensors (e.g. temperature, oxygen, etc.), which may be connected to avehicle processing circuit, may be applied in the exhaust system tomonitor the functioning of the system.

Example 29

For an application as a heat sink, the molded ordered porous structureis formed from a heat conductive material. The heat conductive materialmay be electrically conductive or may be electrically non-conductive.The structure is then formed into a heat sink structure.

A heat conductive thermal interface material is applied to the structurewhose heat is to be dissipated by the heat sink structure, and the heatsink is placed on top of the thermal interface material such that thethermal interface material is sandwiched between the heat generatingitem and the heat sink structure. The thermal interface material may beformed from any number of malleable heat conducting materials,preferably in the form of a layer of paste.

A heat transfer fluid (air, water, etc.) may be moved (pumped, blown,etc.) through the spaces/pores of the heat sink structure in order toaid in dissipation of the heat by the heat sink structure.

Example 30

A molded ordered porous structure is formed from a bio-compatiblematerial. The structure is used in an orthopedic application as ascaffold for bone replacement.

Example 31

A molded ordered porous structure is formed from a bio-compatiblematerial. The structure is used in orthopedic application as a scaffoldfor tissue engineering.

Example 32

A molded ordered porous structure is formed from a bio-compatiblematerial. The structure is used for cell growth.

Example 33

A molded ordered porous structure is formed from an inert material. Thestructure is used to support the catalyst.

Example 34

A molded ordered porous structure is formed from an inert material. Thestructure is used in a packed bed reactor.

Example 35

A molded ordered porous structure is used in a filtration application byusing the pores for size exclusion.

Example 36

A molded ordered porous structure is used as a filter in a filtrationapplication for filtering molten metal.

Example 37

A molded ordered porous structure is used as a filter in a filtrationapplication for high temperature gas filtration.

Example 38

A molded ordered porous structure is used as a radiant heater. Thestructure is attached to a heat source and is used to transfer heat intothe atmosphere.

Example 39

A molded ordered porous structure is formed from a ceramic material andused as part of a high temperature kiln furniture. The molded orderedporous structure is used to move the structure being fired or sinteredin the kiln. The structure is designed to have sufficient porosity toavoid absorbing too much heat and sufficient strength to be able tocarry the item being placed into the kiln.

Example 40

A molded ordered porous structure is used in an absorption application.The structure is used as part of a desiccant.

Example 41

A molded ordered porous structure is formed as a ceramic matrixcomposites (CMC). These structures can be filled with a metal to producea metal matrix composite. In particular, they may be filled with hightemperature performing alloys such as refractory alloys or INCONEL.

Example 42

A molded ordered porous structure is formed as a Metal Matrix composite(MMC). Depending on the design, structures can be developed where thepore volume is more than 50%. In these case, if the pores are filledwith a metallic material through squeeze casting for example, then a MMCstructure will be obtained.

Example 43

A molded ordered porous structure is formed as a polymer matrixcomposite (PMC). These materials are formed when the ordered structuresare made from metallic or ceramic material and the pores are filled witha polymer.

Example 44

A structural material for buildings and other structures is made using amicroporous material made from steel as described above. The structuralmaterial may be surround by a concrete shell to form the structure.

Example 45

A structure is made as disclosed in Example 1, except that the finalstructure is not sintered to full density by sintering at a lowertemperature thereby forming microporosity within the struts of themolded ordered porous structure of TCP. These pores can be loaded withactive biological agents.

Example 46

A bioresorbable material is used to form a molded ordered porousstructure. The bioresorbable portion of the structure is used as abarrier to another material (e.g. drug) contained within the moldedordered porous structure.

Illustrative Embodiments

The following illustrative embodiments are given by way of example andare not intended to limit the scope of the invention claimed below.

One embodiment is directed to a method for forming a porous structure.The method includes injecting a material into a mold to form a moldedproduct, the mold comprising multiple layers of shaping elementsextending through a cavity, each layer of shaping elements includingmultiple shaping elements; and removing the molded product from themold.

Another embodiment is directed to a method for forming a porousstructure. The method includes injecting a material into a mold to forma molded product, the mold comprising multiple layers of shapingelements extending through a cavity, each layer of shaping elementsincluding multiple shaping elements; and removing the molded productfrom the mold.

Another embodiment is directed to a method for forming a porousstructure. The method comprises injecting a material into a mold to forma molded product, the mold comprising at least 15 pins extending througha 400 cubic millimeter area of the mold; and removing the molded productfrom the mold.

Another embodiment is directed to a method for forming a porousstructure. The method comprises injecting a material into a mold to forma molded product, the mold comprising a plurality of shaping elements,the mold configured to provide a porous molded product that is porous inthree dimensions; and removing the molded product from the mold.

Another embodiment is directed to a method for forming a porousstructure. The method comprises injecting a material into a mold to forma molded product, the mold comprising multiple layers of shapingelements extending through a cavity, each shaping element in at leastone of the layers being separated from each other shaping element of thelayer by a distance of not more than about 3 mm; and removing the moldedproduct from the mold.

Another embodiment is directed to a mold for forming a molded product.The mold comprises a pin carrying element comprising a plurality of pinscarried by a first body; a second body having a plurality of spacesconfigured to receive the plurality of pins; and a third body having aplurality of spaces configured to receive the plurality of pins. Themold is configured such that a pin carried by the pin carrying elementcan extend through a first space in the second body and a second spacein the third body such that the first space and the second space areseparated by a cavity of the mold.

Another embodiment is directed to a mold for forming a molded product.The mold comprises a first pin carrying element comprising a firstplurality of pins carried by a first body; a second pin carrying elementcomprising a second plurality of pins carried by a second body; and athird body having a plurality of spaces configured to receive theplurality of pins. The mold is configured such that a first pin of thefirst plurality of pins can extend through a first space in the thirdbody at a first angle and a second pin of the second plurality of pinscan extend through a second space in the third body at a second anglethat is different than the first angle; and the mold is configured suchthat the first pin and the second pin cross and contact each other in acavity of the mold.

Another embodiment is directed to a porous structure comprising aplurality of structural members defining the porous structure havingpores in three dimensions, the structural members having a shape thatincludes at least four sides. The shape may include at least 6 or atleast 8 sides. The width of the shape from a first side to a second sidemay not be uniform. The first side of the shape may be smaller than asecond side of the shape opposite the first side. The shape may be aparallelogram.

Another embodiment is directed to a mold for forming a molded productcomprising multiple layers of overlapping pins, each layer of themultiple layers of overlapping pins located at an angle relative to thelayers of pins above and below that layer of pins.

Another embodiment is directed to a mold for forming a molded productcomprising multiple layers of overlapping pins, each layer of themultiple layers of overlapping pins located at an angle relative to thelayers of pins above and below that layer of pins.

Another embodiment is directed to a mold for forming a molded product.The mold comprises a first pin carrying element comprising a firstplurality of layers of pins carried by a first body; and a second pincarrying element comprising a second plurality of layers of pins carriedby a second body. The mold is configured such that the first pluralityof layers of pins and the second plurality of layers of pins areinterlaced and pins of the first plurality of layers of pins contactpins from the second plurality of layers of pins.

Another embodiment is directed to a method for forming a porousstructure. The method comprises injecting a material into a mold to forma molded product comprising a ceramic lattice; and removing the moldedproduct from the mold.

Another embodiment is directed to a structure comprising a lattice ofstruts defining spaces having passages between intersections of thespaces, where the lattice comprises spaces that pass straight throughthe structure from a first side of the structure to a second side of thestructure; and where more than 70% of the passages of the spaces have anaverage cross-sectional area of about 2500 square microns to about 1square centimeter.

Other embodiments are directed to a method or product according to oneof the above-mentioned embodiments, wherein the molded ordered porousstructure is used in an application. These embodiments include animplant that comprises a molded ordered porous structure, a heattransfer device comprises a molded ordered porous structure, a systemthat comprises a molded ordered porous structure having cells locatedwithin the pores, a filtration system that comprises a molded orderedporous structure, an electronic device having a processor and a heatdissipating structure coupled to the processor where the heatdissipating structure comprises a molded ordered porous structure, orany other application discussed above.

In some embodiments the mold may be configured such that multiple pinsof each layer of pins at least extend through a portion of the moldhaving a volume of up to 10 cubic centimeters, up to 1 cubic centimeter,up to 10,000 cubic millimeters, up to 1000 cubic millimeters, up to 500cubic millimeters, up to 100 cubic millimeters, up to 50 cubicmillimeters, up to 10 cubic millimeters, up to 5 cubic millimeters, upto 1 cubic millimeter, and/or over 10 cubic millimeters.

If shaping elements (e.g. pins) are referenced below as extendingthrough at least a particular volume, the portion of the mold by whichthe volume is judged may be a space defined by walls of the mold (e.g.walls of pin carrying members, an L member, end members, etc.), theportion may only be part (e.g. subset) of such a space (e.g. where theportion is smaller than the total space defined by such mold walls), ormay be some other portion having a defined, regular shape. Each of thepins may extend fully within this volume, may extend only partiallywithin the volume, may only have a small portion of the pin whichextends in the volume, etc. The total volume defined by the pins may belarger than the volume of the mold through which the pins are said to atleast extend.

Any of these illustrative embodiments may include one or more of thefeatures discussed in more detail above.

1. A mold for forming a molded product, comprising: a first pin carryingelement comprising a first plurality of layers of pins carried by afirst body; and a second pin carrying element comprising a secondplurality of layers of pins carried by a second body; wherein the moldis configured such that the first plurality of layers of pins and thesecond plurality of layers of pins are interlaced and pins of the firstplurality of layers of pins contact pins from the second plurality oflayers of pins; first plurality of layers of pins and the secondplurality of layers of pins have at least 100 points of contact withinan area of up to 1000 cubic millimeters.
 2. The mold of claim 1, whereinsubstantially all of the pins in the first plurality of pins have across-sectional diameter less than about 500 microns.
 3. The mold ofclaim 1, wherein substantially all of the pins in the first plurality ofpins have a length of less than about 125 mm.
 4. The mold of claim 1,wherein each layer of the first plurality of layers of pins and thesecond plurality of layers of pins includes multiple pins.
 5. The moldof claim 1, wherein the mold is configured such that multiple pins ofeach layer of the first plurality of layers of pins and the secondplurality of layers of pins at least extend through a volume of the moldhaving a volume of up to 10 cubic centimeters.
 6. The mold of claim 1,wherein the mold comprises multiple layers of shaping elements extendingthrough a cavity, each layer of shaping elements including multipleshaping elements; and the multiple layers of shaping elements includelayers of shaping elements that extend in at least two directions; andthe shaping elements have at least 100 points of contact within an areaof up to 1000 cubic millimeters.
 7. The mold of claim 6, wherein each ofthe layers of shaping elements of the multiple layers of shapingelements is configured to at least extend through a portion of the moldhaving a volume of up to about 400 cubic millimeters.
 8. The mold ofclaim 6, wherein the mold further comprises a plurality of additionallayers of pins extending in the same direction as the multiple layers ofshaping elements.
 9. The mold of claim 6, wherein substantially all ofthe shaping elements of the multiple layers of shaping elements have anaverage cross-sectional diameter less than about 1 millimeter.
 10. Themold of claim 6, wherein substantially all of the shaping elements ofthe multiple layers of shaping elements have an average cross-sectionaldiameter less than about 100 microns.
 11. The mold of claim 1, wherein amolded product formed by injection of a material into the mold has aporous structure, which comprises a multiplicity of ordered structuralmembers defining the porous structure having pores that extend in threedimensions, the multiplicity of structural members intersecting to formstructural member intersections, substantially all of the structuralmember intersections being essentially fluid, and a multiplicity of thepores defined by the multiplicity of structural members substantiallyextending in a natural direction.
 12. The mold of claim 11, wherein themultiplicity of structural members comprise at least about 100 points ofcontact within an area of up to about 400 cubic millimeters.
 13. Themold of claim 11, wherein the multiplicity of the pores defined by themultiplicity of structural members that substantially extend in anatural direction comprise pores extending in a plurality of differentnatural directions.
 14. The mold of claim 11, wherein substantially allof pores the multiplicity of structural members have substantially asame shape.
 15. The mold of claim 11, wherein substantially all of thepores defined by the multiplicity of structural members extend straight.16. The mold of claim 11, wherein a multiplicity of the pores defined bythe multiplicity of structural members are at least partially tapered.17. The mold of claim 11, wherein substantially all of the pores definedby the multiplicity of structural members are about a same size.
 18. Themold of claim 11, wherein the porous structure comprises pores that areessentially interconnected with each other.
 19. The mold of claim 11,wherein the multiple layers of structural members include layers ofstructural members that extend in at least two directions; and thestructural members have at least 100 points of contact within an area ofup to 400 cubic millimeters.
 20. The mold of claim 11, whereinsubstantially all of the pores have a cross-sectional diameter less thanabout 500 microns.
 21. The mold of claim 11, wherein the multiplicity ofstructural members comprise at least about 100 points of contact withinan area of up to about 400 cubic millimeters; and substantially all ofthe pores have a cross-sectional diameter less than about 100 microns.